Saturn ends retrograde motion

Dominic Ford, Editor
From the Outer Planets feed


Objects: Saturn

Saturn will reach the end of its retrograde motion, ending its westward movement through the constellations and returning to more usual eastward motion instead. This reversal of direction is a phenomenon that all the solar system's outer planets periodically undergo, a few months after they pass opposition.

The retrograde motion is caused by the Earth's own motion around the Sun. As the Earth circles the Sun, our perspective changes, and this causes the apparent positions of objects to move from side-to-side in the sky with a one-year period. This nodding motion is super-imposed on the planet's long-term eastward motion through the constellations.

The diagram below illustrates this. The grey dashed arrow shows the Earth's sight-line to the planet, and the diagram on the right shows the planet's apparently movement across the sky as seen from the Earth:


The retrograde motion of a planet in the outer solar system. Not drawn to scale.

2130 apparition of Saturn

11 Feb 2130 – Saturn enters retrograde motion
20 Apr 2130 – Saturn at opposition
30 Jun 2130 – Saturn ends retrograde motion

Observing Saturn

Saturn leaves retrograde motion as its 2130 apparition comes to an end, although it will remain visible for some weeks in the dusk sky.

Its celestial coordinates as it leaves retrograde motion will be:

Object Right Ascension Declination Constellation Magnitude Angular Size
Saturn 13h37m50s 7°25'S Virgo 0.4 17.7"

The coordinates above are given in J2000.0.

From Cambridge , it will become visible at around 20:59 (EST), 37° above your south-western horizon, as dusk fades to darkness. It will then sink towards the horizon, setting at 01:22.

Over the following weeks, Saturn will reach its highest point in the sky four minutes earlier each night, gradually disappearing into evening twilight.

The sky on 26 Nov 2024

The sky on 26 November 2024
Sunrise
06:46
Sunset
16:13
Twilight ends
17:53
Twilight begins
05:06


Waning Crescent

16%

25 days old

Planets
Rise Culm. Set
Mercury 08:21 12:45 17:10
Venus 10:11 14:36 19:00
Moon 02:14 08:04 13:43
Mars 20:26 03:53 11:20
Jupiter 16:56 00:27 07:58
Saturn 12:46 18:17 23:48
All times shown in EST.

Source

The circumstances of this event were computed using the DE430 planetary ephemeris published by the Jet Propulsion Laboratory (JPL).

This event was automatically generated by searching the ephemeris for planetary alignments which are of interest to amateur astronomers, and the text above was generated based on an estimate of your location.

Related news

30 Jun 2130  –  Saturn ends retrograde motion
23 Feb 2131  –  Saturn enters retrograde motion
03 May 2131  –  Saturn at opposition
13 Jul 2131  –  Saturn ends retrograde motion

Image credit

© NASA/Cassini

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